Mark Gale

It would be cheaper and easier to tune the operating system by swapping out weights in your buffer assembly and/or changing the action spring.

Is the barrel chrome-moly or stainless steel? Turning one of their chrome-moly barrels is a bad idea.

Isn't the Independence brand re-manufactured?

Well said... A hammer forged barrel is not a guarantee of anything except higher cost.

Bolts don't bounce, carriers do. That being said, carrier bounce isn't likely to be an issue for you unless you are running a fully adjustable trigger with the pre-travel and over-travel set at nearly zero. @reptoid - For your trivia today question: What malfunction is induced by carrier bounce?

The size of the gas port is the other half of this equation. That being said, barrels with different size gas ports are going to have different sweet spots.

@jkrispies - What do you hope to gain with this barrel over a proven configuration? If this is a "because it's there" issue, I'm OK with it. I just don't think your going to find any upside to it.

If we were discussing muzzleloaders, air rifles or benchrest rifles, your comment may have some merit. We aren't... In the context of a 3G Hoser, splitting hairs over milliseconds is inane.

What exactly is the lock time on this trigger? How much faster is it than say a Geissele SD-3G? I'm inclined to run from anyone who throws out claims like "fastest on the planet". Just sayin' ...

This statement from their website should make you run away from this trigger, "The skeletonized hammer combined with our exclusive .043 double double wound polished piano wire hammer spring make for the fastest lock time on the planet."

Is this officially a clue?

I thought I was the only person still using LSA. I had not even hear LSA since my early days in the Army. Who sells it? I haven't bought any in years but I see it at the gun show all the time. If anyone has it Sarco will. Watch out though, I ordered some Valmet parts from them last month and they have a minimum order amount so it likely won't be cost effective to buy it from them.

LSA is still far and away the best firearms lubricant. It's still manufactured by Castrol Speciality Products Division and Helmuth Behn in Germany, its been around forever and it flat out works. A quart usually runs less than $10 and unless you have a Title II arsenal it would likely last you a lifetime.

I've shot cases of the steel match ammo and experienced the issue intermittently. It disappeared when I started using a USGI hammer spring in my training rifle with a SD-3G trigger. I'm only interested in helping you get through the ammo without spending inordinate amount time chasing down a solution.

You meant to say failure to fire... I doubt this is a Hornady problem. Fire control or bolt group.

Define misfire...

A port door is a good thing on a fighting gun. I just don't see the need for it on a competition gun. Just think of all that extra weight...

Much harder than you could ever expect with a drill press, drill bits and a tiny budget.

If your looking for a nice forged upper receiver without a forward assist for a race gun build, take a look at the variant that V7 offers. I ordered a pair of them and they landed yesterday. I'll post a few photos after I get the upper built. They also make quite a few lightweight upper & lower parts. V7 Weapon Systems

Wrong shape for starters. I contacted them via bookface with a few questions about the design. I haven't received an answer. That being said, it looks like the post linking to the G&A article has been removed from their timeline.

Of course you meant to say carrier bounce... Carrier bounce is not an issue that needs to be resolved unless you are experiencing a malfunction as result of it. It's uniquely a select fire issue and is extremely rare to the extent that it causes an issue with an AR-15. That being said, the overall weight of the buffer assembly really has nothing to do with the phenomenon. The reciprocating mass, or lack thereof, inside does. I'm no spring engineer but I don't believe trimming coils will reduce spring rate, only the number of active coils. Muzzle movement is not always a parts issue. Learning to shoot the carbine properly will have a big affect on muzzle control. Muzzle control is largely a body position and weapon interface issue. I'd suggest you start shooting a local 3 gun or rifle match and attend a shooting class or three with a reputable instructor.

I to am curious but this quote is problematic for me: “We made a large chamber under a small gas port with another chamber on top. That creates a venturi. The venturi effect forces the gas coming through the port to speed up but also lowers the pressure.” Excuse my crude drawing but it will illustrate my concern. I'm guessing they increased the diameter of the gas port on both the low and high pressure side. If this is the case, use of the term venturi would be a red herring. The design may very well have a positive effect on the gas system but it isn't a venturi effect. The larger questions for me are: What is the initial diameter of the gas port in the bore and what effect will the larger size have on the projectile? Will the reduced length of the actual gas port subject it to faster erosive effects?

Your design is very similar to a number of comps in a wide and deep market. If this is just a one off project to make chips and burn time, cut away. If it's a commercial beginning, it's going to be expensive and it's gonna hurt...

From their bookface page...

First I'd open the gas block up a few turns and see what happens. Second, your action spring could be contributing to the problem especially if it's an extra power variant. I'd also meticulously check every leg of the gas system for leaks from the gas block to the bolt rings. If more gas doesn't turn out to cure the the issue, it's likely one of the parts or a combination thereof. Doug H.'s experience illustrates a lack of understanding not of the gas system but gas itself. Switching from low pressure 223 to high pressure 556 doesn't necessarily equal a faster bolt group speed. It likely had the opposite affect. He could have tested this by opening his gas block a turn or so at which I point I'm certain his malfunction would have evaporated. Gas pressure and volume are inversely proportional to each other. Always has been and always will be.